The Borg started off on The Next Generation TV series as pretty scary, anonymous, hive-like robotic villains that were quite effective as bad guys because of that very anonymity - you could take out a dozen of the cyborg suckers, but two dozen more would take their place. So when the Borg Queen was introduced in 1996's Star Trek: First Contact, the idea of a single entity calling the shots for Picard's ultimate foes was a tad disappointing. But the character itself emerged as a formidable opponent, plaguing not one but two Federation captains who liked to duke it out sporting Federation-issue wife beaters, a la John McClane.

The Borg Queen had a two-note personality: Assimilate everything and do so in a permanent slimy sheen. Picard hunted her down and put her spine and skull on his mantle, but that didn't stop BQ from plaguing Janeway and the Voyager crew. The leader of the Borg is seemingly immortal, and unstoppable. If spine-snapping, two-fisted Picard action can't end her, then nothing can. We most likely haven't seen the last of her.

Oh c'mon, you were expecting someone else. This product of late 20th Century genetic engineering chased Kirk 'round the moons of Nibia and 'round the Antares Maelstrom and 'round Perdition's flames before going up in Genesis Device explosion. That, and the hair, and the pecs – guy's hard core.

Khan made it fashionable for Trek villains to check "revenge" as motive on their applications for intergalactic baddie. Having been marooned on Ceti Alpha V for 20 years following his attempt to steal Kirk's ship and murder him, Khan and his band of roadies for RATT took up reading, forging makeshift bungalows for brooding and finding how Ceti Alpha eels work to make people go crazy. If we had that much time on our hands, we'd find better haircuts, but we digress… Khan responded to the USS Reliant's visit with mutiny, taking over the ship and putting it on a direct course for attempt number two to kill Kirk.

Khan's superior intellect is offset by his bloodletting talents and it is only outmatched by his ego, a weakness Kirk exploited to defeat Khan. Like a true villain, Khan didn't go out alone, as his final attack on Enterprise put events into motion that would lead to Spock's death. Taking Kirk's hetero lifemate with him is cause for even more revenge, but that's kinda hard even for Kirk to do, seeing as how there isn't a Dust Buster strong enough to pick up whatever's left of Mr. Noonien Singh.

Regardless, it has been more than 20 years since Khan's wrath. Fans and even those with a passing interest in the franchise know his name. (Kirk yelling it inside a planet, loud enough for all of space to hear, may have something to do with that.)